The present invention is directed to digital communications. More particularly, the present invention is directed to the multiplexing of packet-based digital data.
As the volume of digital data sent over communication lines rapidly grows, there is a continuous need for high bandwidth communication links. One specific need is for 10 Gb/s capacity links for enterprise networks to transmit packet-based data such as Ethernet data. However, there is not a generally available data link supporting Ethernet packet transmission at 10 Gb/s data rates because there are no enterprise switching and routing products that can support 10 Gb/s Ethernet interfaces at this time.
Presently, statistical multiplexing on a packet-by-packet basis multiplexes lower-rate channels in a local area network (xe2x80x9cLANxe2x80x9d) environment. For example, in LAN switches, Ethernet frames are multiplexed onto a higher-speed port frame-by-frame. Although the framing structure is usually preserved, Ethernet frames of different rate (e.g., 10/100/1000 Mb/s) have different encoding standards, requiring decoding and coding before and after multiplexing.
Other multiplexing techniques are possible that do not require a new standard because they involve combining or xe2x80x9ctrunkingxe2x80x9d of multiple links to a link of higher aggregate capacity. One example is xe2x80x9cEtherchannelxe2x80x9d that uses multiple pairs of wires or fibers that behave like a single data link of higher capacity. A different multiplexing scheme that is more efficient in its use of wiring is the wavelength-division-multiplexing (xe2x80x9cWDMxe2x80x9d) of individual data links onto a single optical fiber using different wavelengths. Similarly, time-division-multiplexing (xe2x80x9cTDMxe2x80x9d) is currently only used when many lower-speed (e.g., 10BASE-T) signals need to be sent over longer distances over a single fiber connection.
The aforementioned multiplexing techniques have significant disadvantages. Specifically, statistical packet multiplexing requires a definition of a new physical (i.e., the PHY-layer) and data-link (i.e., the MAC-layer) standard every time a LAN standard of higher speed is required. This standardization process can take years. It also requires buffers at least a few packets deep. Channel trunking or link aggregation is very wasteful with respect to wiring. WDM multiplexing is expensive over distances that do not require optical amplifiers because of the high cost of WDM optical components.
Based on the foregoing, there is a need for an improved method and system for high-speed transmission of data by multiplexing packet-based communication links.
One embodiment of the present invention is a system for data transmission and communication. The system receives a plurality of Gigabit Ethernet data packets from multiple Gigabit Ethernet links. The system bit multiplexes the data packets, on a bit by bit basis, together onto a fiber optic link. At the output of the fiber optic link, the bits are demultiplexed into data packets and transmitted onto multiple Gigabit Ethernet links. The high speed fiber optic link transmits the data at higher speed than is possible over each individual Gigabit Ethernet link.